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Yeigh, T 2012, 'Inhibition & mental effort: a moderation hypothesis', PhD thesis, Southern Cross University, Lismore, NSW.

Copyright D Yeigh 2012


This investigation addresses the relationship between cognitive inhibition as an executive function of the working memory system and cognitive load as the mental effort experienced in relation to classroom learning. The argument advanced and tested is that cognitive inhibition moderates cognitive load, and thereby provides an explanatory mechanism for extrinsic forms of cognitive load. The implications of this relationship are identified and discussed in relation to instructional design.

The relevant literature shows a limited appreciation of the importance of the role played by cognitive inhibition in relation to cognitive load, and, indeed, in relation to learning outcomes in general. Against this background, an empirical investigation of how inhibitory processing differences interact with cognitive load was performed for 114 Year-8 (8th-grade) students. Cognitive inhibition for each student was estimated using the Attentional Networks Test (Posner & Fan, 2005). Student self-reports were employed to estimate individual cognitive load. The relationship between cognitive inhibition and cognitive load was examined across 16 different classroom learning activities, separately involving four teachers. Correlation matrices and ANOVA tests were used to analyse relationships. Achievement outcomes, as indicated by teacher-awarded marks, were also analysed in relation to both cognitive inhibition and cognitive load.

A statistically significant relationship between cognitive inhibition and cognitive load occurred in classes conducted by three of the four teachers. This relationship remained statistically significant even when controlling for a range of other individual differences. The strength of this relationship, however, varied according to the style of the teachers. Achievement outcomes were not significantly related to cognitive inhibition, yet the direction of the association consistently found does suggest that a relationship also exists between cognitive inhibition and achievement outcomes.

The overall results support the need for cognitive inhibition to be considered as a distinct element in the design of a comprehensive, cognitive-based pedagogy. In light of the results, two instructional strategies that involve reduced mental effort and increased instructional efficiency are proposed. Future research investigating the efficacy of these strategies in terms of their impact on cognitive load and achievement outcomes is discussed.